Cold Running SHO...

[illSHOyou]

I am probably most likely seeking sdpatts opinion on this one, but I would like everyone's opinion. Winter is just around the corner and the weather is starting to get cool outside (35-50 degrees.) I believe my SHO is running too cool and afraid that it might be running in cold start up mode. Now I don’t want to just deem the thermostat stuck. I want to make sure there are no other factors.

Anyway, last winter the SHO typically ran just under the “L” in the extreme cold weather, with the police grill. However, this year I put a single 2.5 exhaust on the car. Ever since installing the new exhaust the car ran a tick cooler, which tells me heat is moving away from the engine better, this is fine in the summer weather, but now the car is having trouble warming up in the cool weather.

Some things I have noticed: Heater is still working, which makes me wonder if the thermostat is even broke? At highway speeds 70mph the car runs just a tick under the first line. 80mph and it starts to run between the C and first line due to more air flow through the radiator. Around town the car is fine. The gauge runs right between the L and first line.

Today I have put a piece of cardboard in front of the radiator the size of what a non-police grill would restrict and the car runs happy between the first line and “L” all day.

So my question? Is the Thermostat failing or what? Also can the thermostat on the SHO completely close? Or is there a bypass pipe so the engine gets at least some constant flow?

Past 2 years maintance: Radiator Flush, New water pump installed at 80,000 miles, 60K complete, previous owner has even installed a new radiator because of the typical OEM junk radiator.

So what do you guy’s think?

Sean
91+ Emerald Green
Police grill, Custom 2.5 exhaust, SS Cold-Air, SS UDP, 80mm MAF, Ted B chip, Rod Shifter, SHOnut Aluminum SFB, IRT Clutch, Ceramic TOB,

 

[shojuan]

Replace your thermostat and gauge sender. http://www.fordpartsnetwork.com
Send me your police grill.

Rick

 

[Tommy's SHO]

You basically described my situation exactly! Last year I changed the radiator and w-pump & and put a 180 degree t-stat. I think the t-stat is the problem here. What temp. is yours rated at and what antifreeze are you using?
Yesterday here in Montreal, Canada it was -7 Celcius (approximately 20 F), and after driving for an hour the SHO was barely touching the L.
PS- I'm using "Red" antifreeze for Toyota.

 

[projectSHO89]

The type of coolant will have virtually no effect on the indicated temperature.

The engine and heater core always have coolant flowing in them. The radiator only flows coolant when the thermostat is open.

As suggested, try a new thermostat and guage sending unit. About 20 bucks total.

Steve

 

[sdpatt]

projectSHO89 spelled it out. However, I wouldn't bother to replace the sender until it failed. My original is still on the job. And the 3.0L engine requires the 180 degree thermostat.